Defects Promoted Topotactic Transformation from Co(OH)2 Nanodiscs to Co3O4 Nano Octahedra
Journal Title: Materials Science-Medžiagotyra - Year 2019, Vol 25, Issue 3
Abstract
Topotactic transformation was one of the most frequently related processes in the synthesis process of cobalt oxide nanomaterials. Microstructural evolution studies of this process inform and enable the process of controlling the shape of the final products. One such topotactic transformation was investigated here, the transition from Co(OH)2 hexagonal nano platelets to Co3O4 octahedra by a hydrothermal method in an ammonia solution. Evolution of phase and microstructure was studied during different stages of the reaction to reveal the criteria which prompt this transformation. A phase transformation from Co(OH)2 to CoOOH and hence to Co3O4 was observed. High resolution transmission electron microscopy and image simulation were utilised to disclose the role of defects in the topotactic transformation. A high density of defects including edge dislocations and displacements was found on the surface of dried Co(OH)2 nano platelets. The coexistence of CoOOH domains embedded in the Co(OH)2 surface indicates the absence of the hydrogen bonds of the starting materials. The breaking of hydrogen bonds leads to bonding variation and the further creation of defects, finally prompting the transformation from Co(OH)2 to CoOOH. The breaking of hexagonally arranged hydrogen bonds creates seeds for the formation of Co3O4.
Authors and Affiliations
Fei Hui, Chunhui Wang, Yanhui Chen, Junfeng Zhou, Pierce Maguire, Hongzhou Zhang
Keywords
Related Articles
- EP ID EP615553
- DOI 10.5755/j01.ms.25.3.22005
- Views 49
- Downloads 0
Preparation of Foamed Phosphogypsum Lightweight Materials by Incorporating Cementitious Additives
As a byproduct of phosphoric acid industry, phosphogypsum has many environmental problems. In order to recycle phosphogypsum to manufacture lightweight building materials, cementitious additives including fly ash, ground...
Microstructure and Magnetic Studies of La1-xSrxFeO3 Nano Particles Fabricated by the Citrate Sol-Gel Method
The paper reports the use the sol-gel auto-combustion method for the preparation of nanocrystalline La1-xSrxFeO3 (x = 00.7). The physical and chemical properties, microstructure, morphology and magnetic properties of th...
Properties of High Temperature Oxidation of Heat-resistant Steel with Aluminium and Copper
The research is focused on a novel aluminum and copper-containing heat-resistant steel. The steel was designed by the material performance simulation software JmatPro, performed high-temperature oxidation tests at 650 °C...
The Effects of Ink Presence on Mechanical, Physical, Morphological and Thermal Properties of Office and Newspaper Fiber-Polypropylene Composites
In this study the effects of ink (offset and toner) presence on the mechanical, physical, morphological and thermal properties of newspaper- and office paper fiber-plastic composites were investigated. Printed and unprin...
The Effect of Nanoparticle Surface State on Trap Level Distribution of Polyimide/Aluminum Nitride-montmorillonite Nanocomposite Films
The electrical properties of polyimide (PI) nanocomposites, which are widely used in microelectronic industry and electrical engineering fields, strongly depend on the surface state of nanoparticles. To explore this depe...